Is it possible to use height maps from substance designer in Blender and how?
After further research it appears that the only reasonable way to make height maps work in Blender is as set out below. The displacement support is still experimental in the latest 2.8 builds. Hope the development team will procure full support in the stable release of 2.8. I'm not sure how all this affects vertex count and render time. Hope this will be helpful to someone.


choose Cycles as render engine;
choose "Experimental" feature set in render settings;
add Subsurf modifier to your mesh, switch it to "simple" and tick "adaptive" on;
create a new material for the mesh;
in Material tab scroll down to "Settings", find "Displacement method" and choose "Displacement and bump";
plug in your height map into Displacement Node.


This video illustrates the above (it is in French though): Video